1. Field of the Invention
The present invention relates to ornamental articles in general, and more particularly to articles of jewelry and methods of making the same with laser-engraved, high contrast images.
2. Description of the Related Art
There are already known various constructions of jewelry articles, such as pendants, rings, earrings, charms or the like, among them such which incorporate real precious metal, especially gold, coins. While jewelry of this type has a high degree of aesthetic appeal to many individuals, both would-be owners and mere observers, it is well beyond the means of many of them. While this limited affordability of such items may contribute to their overall appeal, there are still many people who would be willing to pay more for a genuine jewelry article containing real gold or other precious metal rather than a cheap imitation, if only it was not that prohibitively expensive.
The advent of laser technology has created diverse possibilities in many fields of human endeavor in that it made it possible to produce various rather intricate products at a relatively low cost by, among other things, using laser rays to produce a variety of patterns on a substrate or in a layer that coats a substrate by causing the material of such layer or such substrate to evaporate to the requisite depth from selected regions and not from others. Examples of arrangements and methods using this approach can be found, for instance, in the following U.S. Pat. No. 3,588,439 to Heller, et al.; U.S. Pat. No. 3,665,483 to Becker, et al.; U.S. Pat. No. 3,832,948 to Barker; U.S. Pat. No. 4,081,653 to Koo, et al.; U.S. Pat. No. 4,156,124 to Macken, et al.; U.S. Pat. No. 4,480,169 to Macken; and U.S. Pat. No. 5,235,154 to Economicos.
As advantageous as the expedients disclosed in these patents may be for the purposes for which they have been developed, they would have only a limited, if any, applicability in the jewelry field, and then only with substantial modifications. Thus, since most if not all of these patents deal with metal-coated substrates, they could have some applicability to, say, costume or gold-plated jewelry, a field that is separate and distinct from and totally unrelated, beyond surface resemblance, to the real precious metal jewelry field. In any event, none of these patents contains any suggestions how their approaches could be applied in the manufacture of real, rather than metal-coated, jewelry.
In my earlier U.S. Pat. Nos. 5,609,043 and 5,799,511, disclosed real jewelry articles and methods of making them with engraved images by directing a laser through a transparent protective element that overlay a precious metal substrate, such as a gold foil or thin disk. The power output of the laser was maintained low enough to prevent the laser from burning holes in the substrate to be engraved, thereby detracting from the aesthetic appeal of the engraved pattern. The laser output power also needed to be kept low to prevent the formation of a latent image on the protective element itself. This latent image tended to blur the visibility of the pattern engraved into the substrate.
Accordingly, it is a general object of the present invention to advance the state of the prior art.
More particularly, it is an object of the present invention to provide a decorative article, especially real jewelry that does not possess the drawbacks of the known jewelry articles of this type.
Still another object of the present invention is to devise a jewelry article of the type here under consideration that not only can be rightfully called a real jewelry article but also does it at a cost amounting to only a fraction of its traditional counterparts.
It is yet another object of the present invention to design the above article of jewelry in such a manner as to be virtually visually indistinguishable from its traditional counterparts unless scrutinized up close.
Another object of the present invention is to improve the contrast and clarity of a laser-engraved image formed on the jewelry article.
A concomitant object of the present invention is so to construct the jewelry article of the above type as to be relatively simple in construction, inexpensive to manufacture, easy to use, and yet reliable in operation.
In keeping with the above objects and others which will become apparent hereafter, one feature of the present invention resides in an article of jewelry comprising a precious metal substrate having a pattern of pits burned in a major surface of the substrate to define an engraved image, an ash residue in the pits and having a color contrasting with that of the substrate, and an optically clear sealing element for sealing the ash residue in the pits to improve the contrast and the clarity of the engraved image visible through the sealing element.
A particular advantage of the jewelry article as described so far is that the substrate is an actual thin gold disk (as opposed to merely a very thin gold-plated layer) and can be rightfully considered real jewelry. Yet, because of the relatively low amount of gold or other precious metal contained in the disk, the cost of the article is a mere fraction of its traditional thicker counterpart, i.e. a gold coin modified to form a piece of jewelry, such as a pendant.
According to an advantageous aspect of the present invention, the substrate is supported by a frame or an annular support having respective inner and outer peripheries. The support may have a circumferentially extending continuous groove on the inner periphery thereof and into which the substrate is partially received. The annular support element is constructed as a split ring having respective spaced end portions defining a gap therebetween. Then, there is further provided means for controlling the size of such gap with attendant tightening of the support element around the substrate, such controlling means including respective projections on the end portions of the support element, one having a through opening and the other a threaded bore, and a screw-like tightening element passing through the through bore and threaded into the threaded bore and having an enlarged head portion engaging the one projection next to the through bore thereof.
It is particularly advantageous when the aforementioned image is a laser-engraved relief on the major surface of the substrate. The relief is formed by directing a laser directly at the surface. The energy density of the laser on the substrate is adjusted to a power level sufficient to scorch, but not burn through the substrate. The ash residue is concomitantly produced from incinerated portions of the substrate. The residue is a grayish-white to black powder that at least partially fills the pits. This darker residue contrasts with the lighter color of the substrate. When the substrate is a gold disk having a yellowish color, the darker residue accentuates the image.
In accordance with this invention, the major surface of the substrate is cleaned, but the ash residue is left intact within the pits. Then, the sealing element may be applied as a coating over the image. The sealing element may be applied in a liquid, paste, or aerosol manner. The sealing element is transparent to visible light and is preferably cured by ultraviolet light, or by a combination of air, heat or time factors. The sealing element may also be a transparent disc made of either glass or plastic. The contrast and the clarity of the engraved relief visible through the sealing element is much improved over the known art.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.